How to

How to clean common rail injectors

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Common rail injectors are found in diesel engines —their job is to optimise combustion to use less fuel and produce fewer pollutants. It works by injecting fuel under high pressure into the combustion chamber, with the vehicle’s electronic control system regulating the amount of fuel that is used to achieve optimum performance. 

Discover how to clean this important part of a diesel vehicle in this How-to video, and find out:

• What equipment you’ll need
• How to clean the solenoid part of the injector
• How to clean a used and new injector
Diesel Fuel Systems How to Technicians 1 min read

Why do common rail injectors need cleaning?

Over time, common rail injectors can suffer from a build-up of deposits which cause the needle to stick.

What are the other causes of a faulty injector?

As well as deposit build-up, a faulty injector could be caused by particle or water contamination. In addition, incorrect installation can cause an injector to become faulty. 

How long do you need to wait for the solvent cleaner to work?

Once it’s been pumped into the rail injector you need to leave the solvent cleaner to work for 45 minutes. You must take care not to leave it for any longer as this can cause damage.  

How can I tell the cleaning process is working?

With a used common rail injector, you will be able to see discoloured cleaning fluid coming out of it during the cleaning process. 

Can the nozzle be cleaned?

The nozzle can only be cleaned if you have an ultrasonic bath to perform the cleaning, otherwise a full re-build of the injector will be required.


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